What areas of water quality do Environmental Health Officers look at?

Bathing waters

We monitor the quality of water in swimming pools, jacuzzis and paddling pools at leisure centres, private health clubs and hotels.

We check the water is regularly monitored for chemical and microbiological quality (bacteria) on a regular basis and investigate complaints of poor water quality.

Mains water

Affinity Water supply the mains water supply in Hertsmere. They are required by the Drinking Water Inspectorate to monitor the quality of the water being supplied to your tap. Below is the link to the DWI Annual Water Quality Report for all the areas and for Affinity Water.


Environmental Health also monitor the wholesomeness of mains water when used in the manufacture of foods and drinks.  In liaison with the local water supplier we carry out investigations in response to any incidents relating to water quality in both domestic and commercial supplies.

Private water supplies

We monitor private water supplies, which is any water supply which is not provided by a mains supply. The majority of private water supplies in Hertsmere are supplied via a borehole, but they could be from a well or spring.

The Private Water Supplies Regulations 2016 apply to all private water supplies intended for human consumption for domestic purposes (e.g. drinking, cooking, food preparation and washing) and water used for food production purposes.

It also covers water supplied by Affinity Water or a licensed water supplier, which is then further distributed by another person (known as a 'private distribution network').

Our responsibilities

For small supplies (of less than 10m3/day) the monitoring is based on the conclusions of a risk assessment.

Larger private water supplies (greater than 10m3/day), and any supplies that provide water for commercial activities, will require a regular check and audit monitoring from the first year.

We are required to:

  • keep records of all private water supplies including private distribution systems, and to submit an annual return to the Drinking Water Inspectorate (DWI)
  • follow certain procedures if we consider a private water supply is unwholesome, including a requirement to investigate the cause and inform the private water supply users if the supply constitutes a potential danger to human health and give such users advice to allow them to minimise any such potential danger.
  • liaise with the Health Protection Agency to seek advice on whether there is potential danger to human health.
  • liaise informally with private water supply owner/users to prevent a potential danger to human health. If an informal approach does not achieve this then there are other options open to us in the regulations, including the serving of notices.


Do you charge for the service?

We can make reasonable charges to cover our costs. See our current fees and charges 2024-2025.

Further information:

The Drinking Water Inspectorate, who are the national body for ensuring the quality of water, provide an annual publication How Good is Your Drinking Water.

If you have a private supply that is currently registered and would like to arrange for a risk assessment or samples to be taken please us on 020 8207 7435 or email environmental.health@hertsmere.gov.uk